US2782565A - Valve grinder - Google Patents

Description

Feb, 26, 1957 A. J. JONES ET AL 9 5 VALVEGRINDER Filed March 25, 1954 2 Shee ts-Sheet 1 INVENTOR Jul/1.1.10: fi/AROL 58 L516 5 )1 A ORNEY 1957 A. J. JONES ET AL 2,782,565

VALVE GRINDER Filed March 25, 1954 2 Sheets-Sheet 2 IIIII l INvENTQRs ALVIN JJONES BY HAROLD E. BALSIGER ATTORNEY 2,782,565 Patented Feb. 26, 1957 VALVE GRINDER Alvin .1. Jones and Harold E. Balsiger, Waynesboro, Pa., assignors to Landis Tool Company, Waynesboro, Pa.

Application March 25, 1954, Serial No. 418,579

Claims. (CI. 51-37) This invention relates to a machine for grinding the seats of poppet valves.

The method of grinding valve seats in most general use at present is to plunge grind to the desired size with or without a reciprocating wheel. Two operations are required to finish a valve seat by this method because a wheel which is subjected to a rough grinding operation does not provide a suitable finish when used for finish grinding even when a slow feed and spark-out are provided for this purpose. This method obviously requires a eparate machine for each operation.

Another method of grinding valve sea-ts consists of a single machine having two wheels, one for roughing and one for finishing. However, even this apparatus requires two separate operations including a change in the relative position of the wheel and work. Such a change involves a complete feed and withdrawal cycle in each position. Another method for performing a grinding operation of this type requires the use of a machine in which the grinding wheel has been shaped with *a tapered surface, or the equivalent, in which the difference in diameter from one end of the wheel surface to the other is the same as the amount of stock to be removed from the work piece. A machine for this purpose requires a special wheel dressing apparatus in order to form the grinding wheel to the desired shape.

It is therefore an object of this invention to provide a machine in which a valve seat may be subjected to rough and finish grinding in a continuous operation using a cylindrical wheel rather than a tapered wheel. A further object is to provide a machine wherein the rough grinding is elfected by one portion of the grinding wheel and the finish grinding by another portion. A further object is to provide a machine in which feed and traverse movements are effected simultaneously.

The invention consists briefly of a machine in which i the grinding wheel is fed in a plunge cut to within a predetermined distance of finish size then traversed across the work while continuing the feeding operation. The feed is stopped at approximate finished size and the traverse movement continued without feed over the portion of the wheelnot used during the feeding movement. Thus, each step in the grinding operation is performed with a portion of the wheel used only for that particular step. The grinding wheel on this machine may be of the same abrasive throughout, or it may have coarse abrasive for rough grinding on the leading edge of the wheel and a fine abrasive for finish grinding on the trailing portion of the wheel.

Obviously, the grinding of valve seats, which is used primarily for the purpose of illustration, is but one of the many types of work for which this invention may be utilized. Furthermore, although the machine. disclosed herein has a traversing Wheel support, the traversing mechanism may b..- applied to the work support without departure from the spirit of the invention.

Figure 1 is a hydraulic and electric diagram.

Figure 2 is an end view of the wheel support.

Figure 3 is a plan view illustrating an alternate structure for providing the traverse movement.

Figure 4 is a diagrammatic illustration of different position of the wheel and work during a grinding cycle.

With the exception of those features which are the subject of this invention and also a few changes in the hydraulic system which are not directly connected with the present invention, the machine disclosed herein is substantially the same as that shown in co-pending application S. N. 213,652, filed March 2, 1951, now Patent 2,678,521, granted May 18, 1954.

The wheel base 10, in addition to being slid ably mounted for transverse movement toward and from the work, is also slidably mounted on guides 311 and 312 on bed 310 for movement longitudinally at right angles to said transverse movement. This longitudinal movement i effected by a hydraulic motor consisting of a cylinder 320 and a piston 321 slid ably mounted therein and connected by means of piston rod 322 to carriage member 323 upon which wheel base 10 is mounted. Fluid under pressure from pump 126 is distributed by valve 330 alternately through lines 331 and 332 to opposite ends of cylinder 320. Valve 330 is shifted to the left by a solenoid 335 against the action of spring 336. The changes in the hydraulic and pneumatic systerns of the chuck, loader and ejector will be described in connection with the description of the machine.

A rod 350 is frictionally supported in block 351 secured to Wheel base 10. In the retracted position of wheel base 10 shown in Figure 2, rod 350 engages LS151 to hold it in open position. At the front end of said rod, a micrometer stop screw 360 is suspended by an arm 361 on rod 350. When wheel base 10 moves to a predetermined forward position, screw 360 engages LS162. The position of rod 350 in block 351 may be adjusted in opposite directions by adjustment of the screw 362 and 363.

Operation In the cycle of operations, the movement of loader piston 30 to the right also moves bracket 34 having a cam surface 36 thereon which closes L837. L837 closes a circuit through normally closed contact 1 of TR to energize solenoid 114 and shift rapid feed pilot valve 115 to the left against spring 116. In this position shown in Figure l, valve 115 directs fluid under pressure to the right hand end of rapid feed valve 119 shifting said valve to the left to direct fluid from pressure supply line 122 through lines 123 and 124 to rapid feed piston 12. At the same time fluid under pressure is supplied directly from pump through a throttle valve 126 to the head end of slow feed piston 13. Piston 12 then shifts wheel base 10 and grinding wheel 11 to grinding position. When slow feed piston 13 completes its movement it operates slow feed jet pressure switch 147. Switch 147 completes a circuit to energize TR.

When the feeding movement of wheel base 10 begins, rod 350 releases switch 151 which completes a circuit to energize CR14. Contact 1 of CR14 closes a circuit to contact 2 of CR16 which serves as a holding circuit after CR16 has been energized.- When the grinding wheel 11 has been advanced far enough to grind the work approximately to finished size, stop screws 360 which has been suitably adjusted, closes LS162 completing a circuit to energize CR16. Contact 1 of CR16 energizes solenoid 335 and contact 2 completes a circuit through contact 1 of CR14 to hold CR16.

Energizing of solenoid 335 shifts valve 330 against spring 336 to its left hand position. In this position, fluid under pressure is directed to the right hand end of cylinder 3213 to shift piston 321 and wheel base 10 to the left. During this movement the work piece 14 is subjected to the remainder of the grinding wheel surface and the feed continues to the end of the slow feed movement. At the end of the slow feed movement, slow feed jet pressure switch 147 closes and starts timer TR. There is a brief spark-out period until TR times out to open contact 1 and close contact 2. During said sparkout period the traverse movement continues until wheel and work are in the position shown in Figure 4c. Opening contact 1 de-energizes solenoid 114, reversing the rapid feed valves and retracting the wheel base 1-3. Contact 2 of TR holds TR through L515]. to prevent closing contact 1 of TR when P8147 opens upon retraction of said wheel base. When said wheel base moves to rear position, LS151 is opened and TR resets. When loader piston 3f resets it closes L537 completing a circuit through TR-1 to feed valve solenoid 114 to start a new cycle.

Retracting wheel base releases LS162 which opens the circuit to CR16. CR16, however, is held through its contact 2 and contact 1 of CR 14. When wheel base It reaches its retracted position, rod 350 opens LS151 de-energizing CR14 and thus also de-energizing CR16. Opening contact 1 of CR16 de-energizes solenoid 335 and spring 336 shifts valve 330 to the right. In this position of valve 339 fluid is directed to the left end of cylinder 320 to shift piston 321, carriage 323 and wheel base 10 to the right to starting position.

The left hand end of chucking valve 154 is connected through line 125 to the rod end of rapid feed piston 12. When pressure from valve 119 is directed to this side of piston 12, it also acts through line 125 to shift chucking valve 154 to the right. In this position, fiuid under pressure from line 156 is directed through line 161 to the right hand end of chuck cylinder 17 shifting chuck piston to the left to open the chuck jaws 15 and release work piece 14. At the same time fluid is directed to the left hand end of sequence valve 301 to shift said valve to the right and permit fluid to pass to the right end of loader valve 62 shifting said valve to the left. In this left hand position of valve 62, air from line 63 is directed through valve 302 to ejector cylinder 22 to actuate ejector piston 21. At the same time air is directed through valve 61 to the right hand end of ejector valve 302 to hold said valve until the ejector has functioned. The ejector piston 21, in moving to the right, engages lever 66 which in turn engages the end of valve 61 shifting valve 61 to the left. Therefore, valve 62 having been shifted previously to left hand position, directs air from line 63 through valve 61 and line 65 to the head end of loader cylinder 31. Loader piston 39 is shifted to the left to place an unground workpiece in the chuck 15. The pressure in line 65 shifts valve 302 to the right connecting ejector cylinder 22 with an exhaust passage. The ejector is then reset by means of spring 23. Valve 62 in its left hand position also directs air from line 63 through the right hand chamber of said valve passage 64, back through the left hand chamber of valve 62 and through line 66 to the left end of loader cylinder 31. Loader piston 30, moving to the right, closes L537 to energize feed valve solenoid 114 to return the grinding wheel to operative position.

1 claim:

1. A grinding machine having a bed, a work support mounted thereon, means for rotatably supporting a work piece on said work support, a grinding wheel support slidably mounted on said bed, means for effecting relative transverse and longitudinal movement between said supports, means including a switch actuated in response to said transverse movement for initiating said longitudinal movement at a predetermined point in said transverse movement and means including another switch operable at a predetermined point in said longitudinal movement for stopping said transverse movement.

2. The method of grinding a work piece which consists in subjecting said work piece to a grinding wheel having a peripheral face width greater than the length of the surface to be ground, feeding the grinding wheel against the work in a plunge grind to within a predetermined distance of finished size, effecting relative traversing movement between the wheel and work until the wheel grinds the work to the desired size, continuing the traverse movement without the feed for a predetermined time so that the surface to be ground is treated by the full width of the grinding wheel, then reversing the feed movement and traverse in that sequence to return the parts to starting position.

3. The method of grinding a work piece which consists in subjecting said work piece to a grinding wheel having a peripheral face width greater than the axial length of the surface to be ground, feeding the grinding wheel against said work in a plunge grind to within a predetermined distance of finished size with one end of the peripheral surface of the wheel engaging the work, then eifecting relative traversing movement between the wheel and work to subject the work to said rest of the wheel surface for finish grinding until the wheel feeds into the desired size, continuing the traverse movement without the feed for a predetermined time so that the surface to be ground is treated by the full width of the grinding wheel, then reversing the feed movement and traverse in that sequence to return the parts to starting position.

4. The method of grinding a work piece which consists in subjecting said work piece to a grinding wheel having a peripheral face width greater than the length of the surface to be ground, feeding the grinding wheel in a plunge grind to within a predetermined distance of finished size with one end of the said Wheel face engaging the work, then effecting relative traversing movement between the wheel and work to subject the work to the rest of the wheel surface for finish grinding while continuing the feed movement until the wheel feeds in to the desired size, continuing the traverse movement without the feed for a predetermined time so that the surface to be ground is treated by the full width of the grinding Wheel, then reversing the feed movement and traverse in that sequence to return the parts to starting position.

5. The method of grinding a workpiece which consists in subjecting said work to a grinding wheel having a peripheral face Width greater than the length of the surface to be ground, feeding the grinding wheel in a plunge grind to within a predetermined point of finished size, effecting relative traversing movement between the Wheel and work while continuing the feed movement until the wheel feeds into the desired size, continuing the traverse movement without the feed for a predetermined time so that the surface to be ground is treated by the full width of the grinding wheel, then reversing the feed movement and traverse in that sequence to return the parts to starting position.

6. A grinding machine having a bed, a work support mounted thereon, means for rotatably supporting a workpiece on said work support, a grinding wheel support slidably mounted on said bed, a grinding wheel rotatably mounted on said support, means for effecting relative transverse and longitudinal movement between said supports, means for effecting said transverse movement with one end of the peripheral face of the grinding wheel in position for engaging the work, means operable at a predetermined point in said transverse movement and in response to said transverse movement for effecting said longitudinal movement while continuing said transverse movement, means for stopping said transverse movement while continuing said longitudinal movement and means responsive to said longitudinal movement for stopping said longitudinal moving means with the other end of said wheel face in engagement with the work.

7. The method of performing rough and finish grinding a single operation on a workpiece having a relalively narrow surface, which consists in subjecting said workpiece to a grinding wheel having a peripheral face width greater than the width of the surface to be ground, effecting a feeding movement between said wheel and work with one end of said wheel engaging the work until a predetermined depth of cut has been reached for a rough grinding operation, initiating a relative traverse movement between said work and wheel while continuing said, feeding movement to provide a finish grinding operation, stopping said feeding movement while continuing said traverse movement to provide a sparkout operation, and stopping said traverse movement after the work has been subjected to the remaining portion of said grinding wheel face.

8. The method of performing rough and finish grinding in a single operation on a workpiece having a relatively narrow surface which consists in subjecting said workpiece to a grinding Wheel having a peripheral face width greater than the width of the surface to be ground, plunge grinding said workpiece with one end of said grinding wheel face for a rough grinding operation to a predetermined depth of cut, moving the grinding wheel axially while continuing said feeding movement to effect a finish grinding operation, stopping said feeding movement while continuing said axial movement for a sparkout grinding operation and stopping said axial movement after the work has been subjected to the remaining surface of said grinding wheel.

9. A grinding machine having a bed, a grinding wheel support slidably mounted on said bed, a grinding wheel rotatably mounted on said support, a work support having means for rotatably supporting a workpiece, means for elfecting relative transverse and longitudinal movements between said supports, means for effecting said transverse and longitudinal movements independently of one another, means for initiating longitudinal movement at a predetermined point in said transverse movement, means for continuing said transverse movement and said longitudinal movement simultaneously, means including a positive stop for stopping said transverse movement when said workpiece has been ground to a predetermined size, and means including a timing device for stopping said longitudinal movement a predetermined interval after the stopping of said transverse movement.

10. A grinding machine having a bed, a work support mounted thereon, means for rotatably supporting a workpiece on said work support, a grinding wheel support slidably mounted on said bed, a grinding wheel rotatably mounted thereon, means for effecting relative transverse and longitudinal movement between said supports, a switch for initiating said longitudinal movement, means on said wheel support for actuating said switch at a predetermined point in said transverse movement, means including a pressure switch operable at a second predetermined point in said transverse movement for stopping said transverse movement and starting a timing device and means actuated by said timing device for stopping said longitudinal movement a predetermined interval after the stopping of said transverse movement.

References Cited in the file of this patent UNITED STATES PATENTS 1,294,024 Arter Feb. 11, 1919 1,891,663 Booth Dec. 20, 1932 1,949,552 Taylor Mar. 6, 1934 1,950,491 Heald Mar. 13, 1934 2,030,335 Svenson Feb. 11, 1936 2,047,869 Harley July 14, 1936

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